The specific aims of this study are 1) evaluate the safety and tolerability of ganaxolone in the treatment of drug-resistant seizures by monitoring adverse events, laboratory evaluation, and vital signs, and measuring ganaxolone plasma concentrations with respcet to dose; and 2) evaluate the efficacy of ganaxolone in the treatment of drug resistant seizures in terms of change in physician's global assessment, and the percentage change in seizures frequency as compared to baseline.